[ARC5] BC-230 first run

[AKLDGUY .]

On 3/30/16, Mike Morrow <kk5f at earthlink.net> wrote:
>> ... what I'm interested in here is how the change to VT-25-A affects
>> the schematic, since my set is the AO and accordingly should have used
>> the VT-25-A.
>>
>> Now, am I wrong to rely on that schematic? What discrepancies should I
>> be aware of? Does this have any bearing on the coil tap that I pointed
>> out
>> elsewhere?
>
> The only change to the schematic of the BC-AO-230 through BC-AS-230 is an
> "-A" after the "VT-25" tube labels.  The tube operating data tables in the
> manuals for these five transmitters did not change with introduction of the
> VT-25-A.
>
> The VT-25-A appears to be electrically identical to the VT-25, but it has
> some internal mechanical differences.  Apparently these were construction
> improvements made without notably altering electrical characteristics.
> Anyone with some real insight into VT-25 vs. VT-25-A might want to join in.
> Do NOT put much faith in anything from the audio-idiot websites where "tubes
> with thoriated filaments sound better than tubes with oxide-coat
> filaments."
>
> So...the schematic is fine.  The info on the original tube variants is of
> historical interest only.


OK thank you. When the VT-25s and VT-25-As turn up in local swap meets,
I'll know which to buy and which to ignore :))

73 de Neil ZL1ANM